【摘要】 针对某600MW超临界对冲燃烧锅炉在低氮技术改造后侧墙壁面出现明显的还原性高温硫腐蚀现象,采用在侧墙添加贴壁风装置方案,并对添加贴壁风装置前后工况进行了全炉膛数值模拟,分析了侧墙壁面附近的烟气成分分布以及贴壁风对炉内燃烧和高温硫腐蚀的影响.结果表明:未添加贴壁风装置的原始工况下,壁面附近CO主要集中在侧墙中心,且O2体积分数较低,模拟所得还原性区域与实测腐蚀位置吻合良好;添加贴壁风装置后,侧墙CO体积分数明显下降,O2体积分数明显升高,壁面的还原性气氛得到有效改善,且此方案对炉内燃烧和污染物排放的影响较小.更多还原

【Abstract】 To solve the problem of high-temperature sulfur corrosion occurring on the side water wall of a600 MW supercritical opposed firing boiler after low-NOxcombustion retrofit,a device was added to arrange near-wall air curtain to the side wall,after which numerical simulation of the furnace combustion was carried out to examine the distribution of flue gas components near the side wall before and after the addition of near-wall air curtain,and to analyze the effects of near-wall air curtain on the in-furnace combustion and high-temperature sulfur corrosion.Results show that under the original condition without near-water air curtain,CO is mainly concentrated in the middle area of water wall with lower concentration of O2,where the simulated region of reducing atmosphere is in good agreement with actual region of sulfur corrosion observed in the boiler;in the case with near-wall air curtain,the CO concentration reduces significantly while the O2 concentration rises simultaneously in the area near the side wall,resulting in greatly improved reducing atmosphere in the area;the adoption of near-wall air curtain has negligible influence on the furnace combustion and pollutants emission.更多还原